<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
  <input type="text" v-model="n1">
  <input type="text" v-model="n2">
  <button @click="f(1)">加</button>
  <button @click="f(2)">减</button>
  <button @click="f(3)">乘</button>
  <button @click="f(4)">除</button>
  <h1>结果:{{result}}</h1>
</div>
<script src="../js/vue.js"></script>
<script>
  let v = new Vue({
    el:"body>div",
    data() {
      return {
        result: "",n1:"",n2:""
      }
    },
    methods: {
      f(x) {
        if (isNaN(v.n1)||isNaN(v.n2)){
          v.result = "输入错误!";
          return;
        }
        switch (x) {
            case 1:
              v.result = v.n1*1+v.n2*1;
              break;
          case 2:
            v.result = v.n1-v.n2;
            break;
          case 3:
            v.result = v.n1*v.n2;
            break;
          case 4:
            v.result = v.n1/v.n2;
            break;
        }
      }
    },
  })
</script>
</body>
</html>